The present invention concerns an air distributor for air-conditioning systems.
Such distributors are called upwelling-air distributors or stratified-air distributors. They usually stand upright on the floor, so that the incoming air flowing out of them toward anyone occupying the air-conditioned space will not have too far to flow. The incoming air flows, especially in high-ceilinged and contaminated industrial spaces, through a relatively uncontaminated region just above the floor. The incoming air accordingly mixes relatively little with the contaminated ambient air before being breathed in by the occupants. Since the source of heat and the source of contamination are usually identical in industrial spaces, the liberated contaminants rise by convection to the ceiling, where they are intercepted by the exhaust system. To maintain this current, the upwelling-air distributors must decelerate the flow of incoming air into the space and accelerate the flow of rising air. This approach will prevent the contaminated air from recirculating back from the ceiling into the space where the occupants are staying or working.
To ensure that the incoming air emerging from an upwelling-air distributor will remain in the occupied space, the air must be denser and accordingly cooler than the rest of the air. The air's tendency to radiate can of course not be exploited for this purpose because it must as hereintofore pointed out be kept low in order to avoid obstructing the contaminated air rising in the vicinity of the machinery. Another result is that less ambient air will be forcibly mixed with the incoming air.
An upwelling-air distributor of the aforesaid genus is known from German OS 4 037 287. It comprises a perforated cylinder with horizontal and vertical components of perforated sheet metal. These components uniformly deflect the incoming air inside the cylinder and supply it horizontally to the space being air-conditioned. The higher density and lower temperature of the air leaving the distributor horizontally, however, provide it with a component that flows toward the floor. This situation is reinforced by the floor's Coanda effect. The stratum of incoming air becomes constricted and considerably accelerated, by a factor of as much as 2 to 3. The result is drafts and increased recirculation of the contaminated ambient air.
Another drawback of known upwelling-air distributors is that they cannot be utilized to heat the occupied space. Any hot air emitted, emerging as slowly as it does, would rise immediately to the ceiling and would not remain where needed. The incoming air can be warmer than the ambient air in summer of course because in most industrial spaces it is not mechanically cooled. Here again the warm incoming air will immediately rise to the roof and only some of it will get to the occupants and only after being recirculated along with the contamination.